Grid · July 26, 2022
Batteries, rates, and the grid you actually live on
A home battery is a rate-structure tool, a backup tool, and sometimes a solar-pairing tool. It is rarely all three at once unless you design it that way.
6 minute read · Anchors Aweigh Energy
Southern California Edison, SDG&E, and PG&E do not bill you the way they did ten years ago. Time-of-use rates, high evening peaks, and the way solar is credited after NEM changes have made a battery look less like a gadget and more like a piece of the service panel.
Three jobs, three designs
- Backup. A critical-loads panel and enough kilowatt-hours to ride a shutoff or a storm. Size to the hours you care about, not the brochure.
- Rate shifting. Charge when power is cheap or when the array is overflowing; discharge into the evening peak. This is software as much as hardware.
- Self-consumption. Keep midday solar on the property instead of exporting it for a weak credit. More important after net-billing than it was under classic NEM.
A system sold as “backup” that is then programmed only for self-consumption will disappoint you the first night the wind takes a feeder down. Decide the job, then size and program to it.
What we will tell you that the proposal will not
Your evening load is not the nameplate of the house. It is the HVAC, the range, the well pump, the EV. A whole-house audit or even a week of interval data will keep you from buying a battery that covers the lights and none of the heat pump.
We do not sell batteries. We will read the proposal against the house and the tariff you are actually on.